Polyetherimide preparation method including addition of macrocyclic polyetherimide oligomers
Macrocyclic polyether oligomers, preferably as mixtures of oligomers of different degrees of polymerization, are incorporated in a direct displacement reaction mixture for the formation of polyetherimides, said reaction mixture comprising at least one alkali metal salt of a dihydroxy-substituted aromatic hydrocarbon and at least one bis(halo- or nitrophthalimide). The macrocyclic oligomers can be isolated from an earlier-prepared linear polyetherimide composition. Their incorporation in the reaction mixture does not increase the proportion of oligomers in the polyetherimide product.
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Claims
1. A method for preparing a polyetherimide composition comprising linear polyetherimides by the reaction of the components of a reaction mixture comprising at least one alkali metal salt of a dihydroxy-substituted aromatic hydrocarbon and at least one bis(halo- or nitrophthalimide), which comprises additionally incorporating in said reaction mixture at least one macrocyclic polyetherimide oligomer having a degree of polymerization from 1 to about 10.
2. A method according to claim 1 wherein a mixture of macrocyclic polyetherimide oligomers having different degrees of polymerization is incorporated in said reaction mixture.
3. A method according to claim 2 wherein said mixture of macrocyclic polyetherimide oligomers comprises oligomers having degrees of polymerization from 2 to about 5.
4. A method according to claim 1 wherein the dihydroxy-substituted aromatic hydrocarbon has the formula
5. A method according to claim 4 wherein A.sup.1 has the formula
6. A method according to claim 5 wherein the bis(halo- or nitrophthalimide) has the formula ##STR4## wherein R.sup.1 is a C.sub.6-20 divalent aromatic hydrocarbon or halogenated hydrocarbon radical, a C.sub.2-20 alkylene or cycloalkylene radical, a C.sub.2-8 bis(alkylene-terminated) polydiorganosiloxane radical or a divalent radical of the formula ##STR5## in which Q is --C.sub.2 H.sub.4 --, --O--, ##STR6## X.sup.1 is fluoro, chloro, bromo or nitro and m is 0 or 1.
8. A method according to claim 7 wherein the bisphenol A disodium salt is employed as a hydrate which is dehydrated prior to forming the polyetherimide.
9. A method according to claim 2 further comprising the step of isolating said macrocyclic polyether oligomers from an earlier-prepared composition comprising linear polyetherimides.
10. A method according to claim 9 wherein the dihydroxy-substituted aromatic hydrocarbon has the formula
11. A method according to claim 10 wherein A.sup.1 has the formula
12. A method according to claim 11 wherein the bis(halo- or nitrophthalimide) has the formula ##STR7## wherein R.sup.1 is a C.sub.6-20 divalent aromatic hydrocarbon or halogenated hydrocarbon radical, a C.sub.2-20 alkylene or cycloalkylene radical, a C.sub.2-8 bis(alkylene-terminated) polydiorganosiloxane radical or a divalent radical of the formula ##STR8## in which Q is --C.sub.2 H.sub.4 --, --O--, ##STR9## X.sup.1 is fluoro, chloro, bromo or nitro and m is 0 or 1.
14. A method according to claim 13 wherein the bisphenol A disodium salt is employed as a hydrate which is dehydrated prior to forming the polyetherimide.
Type: Grant
Filed: Mar 17, 1997
Date of Patent: Jan 5, 1999
Assignee: General Electric Company (Schenectady, NY)
Inventor: John Christopher Schmidhauser (Niskayuna, NY)
Primary Examiner: John M. Cooney, Jr.
Attorneys: Noreen C. Johnson, Douglas E. Stoner
Application Number: 8/818,987
International Classification: C08G 1710;
